The present invention relates to improved medical instrumentation usable in the field of electromyography (EMG), i.e. for the sensing, selective development and recordation of electrochemical nerve impulses as transmitted through the nervous systems and muscles of humans and animals. Specifically, the invention involves a wireless transmitter to which mono or bipolar medical electrodes are directly connectable and from which electrical signals are transmitted by radiant energy to remote but associated receiver and audio or visual display or recorder equipment.